MOSCOW, Mar. 22 (Press Shia) – ISIL executed possibly hundreds of detainees between 2014 and 2015, leaving the bodies in a sinkhole eight kilometers (about 5 miles) from western Mosul, a city in Iraq, Human Rights Watch (HRW) said Wednesday in its press release.

The organization urged Iraqi authorities to mark the site and turn it into a memorial.

“The Islamic State (also known as Daesh) executed and dumped the bodies of possibly hundreds of detainees at a site near Mosul… Multiple witnesses told Human Rights Watch that the bodies of those killed, including bodies of members of Iraqi security forces, were thrown into a naturally occurring sinkhole at a site known as Khafsa, about eight kilometers south of western Mosul,” the organization said.

“If exhumation is possible, the process should be carried out under international standards,” the organization said.

The Iraqi government forces backed by the US-led international coalition forces are currently leading an operation to free western Mosul from the terrorists. The eastern part of the city was liberated in January.